Causes

The exact cause of a prolonged pregnancy is unknown. About 5%-10% of pregnancies become post-term.

Risk Factors

Previous post-term pregnancy is the most common risk factor. Other factors may include first pregnancy, obesity, and older maternal age.

Symptoms

If you are still pregnant after your due date, see your doctor.

Diagnosis

Your medical history will be reviewed to make sure that your due date is correct. Your doctor may advise:

Ultrasound
—To measure amniotic fluid and see how much your baby is moving

Fetal monitoring—To check the baby's heartbeat

Your doctor may also check your cervix to see if it is opening and thinning in preparation for labor.

Treatment

Talk with your doctor about the best treatment plan for you. Treatment options include the following:

Expectant Management

Some women and their doctors choose to wait for labor to begin on its own. During this period, the doctor will closely monitor the baby’s heart rate, amniotic fluid levels, breathing, and movement. If there are any signs of problems or your pregnancy continues beyond 42 weeks, your doctor may recommend labor induction.

Labor Induction

If labor has not started naturally, there are a number of ways your doctor can try to induce labor.

Medications can help soften and open the cervix.

A small tear is made in your amniotic sac to break your water. This is painless and can trigger contractions.

Your doctor may do a membrane sweep. Your doctor uses a finger to sweep around the neck of your cervix to separate it from the membranes around your baby. This action releases hormones called prostaglandins, which may induce labor.

Your doctor may give you a medication called oxytocin. Oxytocin starts contractions and helps them to remain strong and regular.

In general, women with a post-term pregnancy who have an induced labor are less likely to need a
cesarean delivery
than women who wait for labor to begin naturally.

Prevention

There is little that can be done in advance to reduce your chances of having a post-term pregnancy. If your pregnancy lasts beyond 42 weeks, talk to your doctor before trying any home remedies for starting labor. Most home remedies are unproven and some may be harmful to you or your baby.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Pregnancy: what to expect when your due date has passed. American Academy of Family Physicians Family Doctor website. Available at:
http://familydoctor.org/familydoctor/en/pregnancy-newborns/labor-childbirth/pregnancy-what-to-expect-when-youre-past-your-due-date.html. Updated August 2010. Accessed February 25, 2016.